Internal-combustion engine



Aug. 12, 1930. P, ARRIGHI' 7 1,772,977

INTERNAL COMBUSTION ENGINE Filed Feb. 25, 1929 2 Sheets-Sheet 1 IN VENTOR.

ATTORNEYS.

Aug. 12, 1930. P. ARRIGHl 1,772,977

' INTERNAL COMBUSTION ENGINE Filed Feb. 25, 1929 2 Sheets-Sheet 2 l LN 4ATTORNEYS.

Patented Aug. 12, 1930 UNITED STATES, PATENT OFFICE,

PIETRO ARRIGHI, or SAN FRANCISCO, CALIFORNIAIASSIGNOR T ITALIEN-AMERICANMOTORS me, or sen FRANCISCO, CALIFORNIA, A CORPORATION or CALIFORNIA"INTERNAL-COMBUSTION GINE Application filed February 25, 1929. Serial No.342,579.

This invention relates to internal cembus-.

The present invention discloses that type of internal combustion enginein which a plurality of cylinders are arranged radially and parallel toa drive shaft, power being transmitted from the reciprocating pistons inthe individual cylinders to the drive shaft through a series ofconnecting rods and crank shafts and a reduction gear drive, so that thedrive shaft will be driven at what is ordinarily termed cam shaft speed.

A number of dili'erent methods of admit ting and exhausting thecombustible mixtures has been employed in engines ofthis' characterbutthey have met with difficulties and inefiiciency.

The object of the present invention is to generally improve and simplifythe construction of the valve mechanism in engines of the characterdescribed; to provide a single;

poppet valve for each cylinder and in combination therewith a singlerotary valve which cooperates and functions in such a manner that eachpoppet valve will alternately function as an inlet and an exhaust valve,and further to provide means whereby the several poppet valves andthesingle rotary valve may be directly driven and actuated by the driveshaft.

The valve mechanism as applied to an en-' gine of the characterdescribed is shown by drawings in which:

Fig. l is a central longitudinal section of the engine, said viewshowing the valve mechanism as applied, the section being taken on lineI-I of Fig. 2.

Fig. :2 is a cross section'taken on line 'II ILFig. 1, F r r Fig. 3- isan end view partly broken away and partially'in section, the sectionportion being taken on line III'III--of Fig. -1.

Referring to the drawings in detail, and particularly to Fig. 1, Aindicates a crank case to which is suitably secured a number ofcylinders generally indicated at B; The cylinders are-disposed radiallyand parallel to a drive shaft generallyindicated atC;

way of illustration in the accompanying This shaft extends through thecrank case and is journalled therein, as indicated at D, and itisdrivenin the following manner: Each cylinder is provided with apiston, such as shown at E, these pistons being provided with connectingrods F which in turn are connected with individual crankshafts,such asshown at G. Each crankshaft has ,se-. cur-ed thereon a spiral gearpinion H, andthe several pinions intermesh with a spiral gear K, whichin tuIILlS keyed or otherwise secured tothe drive shaft C, thegear'ratio be tween the spiral gear pinions H and the spiral gear Kbeing 2 to 1, so that the drive shaft will make one revolution to eachtwo revolutions of the individual crank shafts. The drive shaft is, inother Words, driven at what is ordinarily termed cam shaft speed.

While a spiral gear drive is shown, itis.

obvious that a bevel or worm gear drive may be employed, the particulardrive shown he I ing of no lmportance as it forms no part of the presentinvention. The present invention is directed to the valve mechanismwhereby the combustible mixture is. admitted and exhausted from thevseveral cylinders. i The valve mechanism consists of a head member 2whichis bolted or otherwise secured to the outer .ends of the cylinders,as indicatedat 3. The head member is provided with aplur ality ofelbow-shaped passages, such as indicated at 4, the number of passagesemployed being equivalent to the number of cylinders,

the number in this instance being. 6 as clearly shown in ig. 2. A valveseat 5 is formed in the outer end of each passageand a poppet valve 6 ofstandard construction is adapted to seat thereon. Thestems of the poppetvalves are disposed at right angles tofithe drive shaft C. They arespring seated, as indicated at/Wand they are lifted from their seats byaicam member generally indicatedat 8, this cam being secured to thedrive shaft or formedintegral therewith, asshown. f

The drive shaft C is not only supported by the journal members D in thecrank case, but it is also supported by journal members, such asindicated at '9 and 10, these journal members being mounted in the head2. In other words,'- the drive shaft extends throughthe registers"withthe elbow-shaped passage 41s head member 2 and it serves three mainfunctions, first that of driving the cam 8 whereby the poppet valves 6are actuated, secondly that of supporting and driving a rotary valvegenerally indicated at 12, and third that of functioning as a portion ofthe inlet manifold, the drive shaft being hollow. or tubular at itsouter end, as indicated at 11, to permit the incoming combustiblemixture delivered by the carburetor 18 to pass therethrough.

The rotary valve is best illustrated in Figs. 1 and 3. It is first ofall provided with an exhaust port 14, and secondly with an' inlet port15, the port 15 being in communication with the carburetor and thetubular passage 11 by means of radial ports 16. The exhaust port extendstransversely through the rotary valve, as shown in Fig. 1, so that whenthe valve indicated at 6 is open, for the purpose of exhausting, theexhaust gases can pass out through the elbow-shaped passage 4 in thedirection of arrow a, then through the exhaust passage 14 and into anexhaust manifold indicated at 17, this manifold being in the form of acover member 18 which retains the rotary valve against endwise movement,the cover being secured to the outer ends of'the cylin ders in anysuitable manner, or as here shown by bolts 19.

By referring to Fig. 3 it will be noted that the inner end of theexhaust port 14 which elongated, as indicated at 14, as it extends fromthe point 19 to the point 20. This is necessary as registration must bemade between the elbow shaped passage 4 and the port 14 duringsubstantially the entire exhaust stroke of the piston. The outer end ofthe inlet passage 15 is similarly elongated, as shown at 15, see Fig. 3,as it extends from the point 21 to the point 22, the length of the portbeing such that registration will be maintainedv between the inlet portand the elbow. shaped passage 4 during the suction stroke of a piston.

The poppet valves employed in the present instance function alternatelyas inlet and as exhaust valves and it is accordingly necessary tomaintain them in an open position both during. the exhaust and the inletstroke. The.

cam 8 is accordingly shaped to maintain the valves open during thisperiod, as clearly shown at 8 in Fig. 2, as it extends from the point 23to the point 24.

The engine is intended to operate on the four-cycle principle, to wit,exhaust intake compression and firing, and as the drive shaft operatesat cam shaft speed due to the gear ratios employed, the valves willremainopen during the exhaust and inlet stroke and they will remainclosed during the compression and filing strokes.

When the engine is in operation, the drive shaft C rotates at cam shaftspeed, and the poppet valves 6 will thus beopened in successive orderand they will remain open during the exhaust and intake strokes.

The rotary valve 12 rotates in unison with the earn 8 as it is keyed orotherwise secured to the drive shaft and the exhaust port 14 willregister with the respective cylinders during the exhaust stroke whilethe intake port 15 will register with the cylinders during their intakestroke. The combustible mixture, when admitted,'will of coursebecompressed in the usual manner and during the firing stroke thepressure exerted is transmitted through the several pistons to rotatethe crank shaftsG and the spiral pinions H, and as these intermesh withthe spiral gear K power is continuously transmitted to the drive shaftG.

The engine may be employed for any purpose desired, but it isparticularly intended for aviation purposes and the like. In that casethe propeller will be secured on the outer end of the drive shaft at thepoint indicated at 40.

An engine constructed in the manner disclosed should be particularlysuited for aviation purposes as sticking or burning of the poppet valvesis entirely eliminated, due to the alternate cooling of the valves 6during the intake strokes. The valve operating mechanism is materiallysimplified as the valve stems are disposed at right angles to theidriveshaft and are, directly actuated thereby through means of the cam 8.-The rotary valve employed is also important as it functions incooperation with the poppet valves first to direct and admit theincoming combustible mixture, and secondly in removingor carrying awaythe exhaust or burnt gases.

A rotary valve such as here shown need not be very tightly packed, asleakage of exhaust gases is of no material importance. Leakage ofincoming gases cannot vtake place as the passage15 is continuouslysubjected to suction. That is, considerable wear, as far as the rotaryvalve is concerned, may take place without impairing the functioning ofthe engine. Such wear might possibly admit a certain amount ofatmospheric air between the elbow shaped ports 4' and the inlet port 15but such leakage or air admission would readily be compensated for byenriching the carbureter. Leakage of exhaust gases would be of noimportance as they are finally dirooted. to the atmosphere in any case.p

The most important feature of all is the provision of a valve mechanismwhich is very simple and which is reliable and dependable under allconditions of load and speed, this being mainly due to the fact that thepoppet valves are directly actuated by the cam on the drive shaft andbecause they alternately function as inlet and exhaust valves, therebypreventing overheating, burning and sticking of the individual valves;

While certain features of the present invention are more or lessspecifically described, I wish it understood that various changes may beresorted to within the scope of the appended claim, similarly, that thematerials and finishes of the several parts employed may be such as themanufacturer may decide, or varying conditions or uses may demand.

Having thus described m invention, what I claim and desire to secure yLetters Patent 1s:

In an engine of the character described, a main drive shaft, a pluralityof cylinders surrounding the shaft with their longitudinal axis parallelto the shaft, a head on each cylinder and each head having a single portformed therein functioning as an inlet and exhaust port, a valvesupporting head centrally disposed between the cylinder heads andsecured to said heads, said valve supporting head having a plurality ofports formed therein one for each cylinder head port and communicatingtherewith, a plurality of puppet valves carried by the valve supportinghead and extending through said last named ports and adapted to open andclose communication between said ports and the cylinder head ports, acentral bearing formed in the valve supporting head to support one endof the main drive shaft, said end of the shaft being hollow andconnected with a carburetor, a rotary valve mounted in the valvesupporting head, said rotary valve havingan inlet port formed therein,one end of said port being in constant communication with V the hollowshaft and the carburetor and the other end adapted to successivelyregister with the cylinder head ports, an exhaust manifold, said rotaryvalve also having an exhaust port formed therein one end being inconstant communication with the exhaust manifold and the other endadapted to suecessively register with the cylinder head ports, a pistonin each cylinder, means whereby reciprocal movement of the piston istransmitted to rotate the main drive shaft at cam shaft speed, a drivingconnection formed between the main drive shaft and rotary valve wherebythe rotary valve will rotate at cam shaft speed, and a single cammounted on the main drive shaft whereby the puppet valves aresuccessively actuated, said cam being so shaped as to retain each puppetvalve open during the exhaust and intake cycle of each cylinder, andsaid rotary valve being so timed as to bring the exhaust and inlet portformed therein into register with the puppet valves when they are open.

PIETRO ARRIGHI.

